Prepayment mechanism for electricity-meters.



PATENTED AUG. 16, 1904.

B. NORTH.

PREPAYMENT MECHANISM FOR ELECTRICITY METERS.

APPLICATION TILED JULY 7,1903;

N0 MODEL.

LIP/EH UT Barker Noxth By his attorney 6W fly Z W Vi Passes fi 3.

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NITED STATES Patented August 16, 1904.

ATENT @FFICE.

PREPAYIVIENT MECHANISM FOR ELECTRICITY-METERS.

SPECIFICATION forming part of Letters Patent No. 767,495, dated August 16, 1904.

i Application filed July 7, 1903. Serial No. 164,568. (No model.)

To all whmn it may concern:

Be it known that I, BARKER NORTH, A. R. C. So, London, F. C. S., lecturer in chemistry, a subject of the King of Great Britain, and a resident of Manningham, Bradford, in the county of York, England, (whose postoflice address is Glenholme, Glenholrne Road, Manningham aforesaid,) have invented certain new and useful Improvements in Prepayment Mechanism for Electricity-hleters, (for which application has been made in Great Britain, No. 17,952, dated August 13, 1902, and in Germany, dated March 14, 1903,) of which the following is a specification.

This invention relates to prepayment mechanism, and has for its object to provide such a construction as will enable a system of prepayment to be adapted in a thoroughly reliable manner to the automatic supply of measured quantities of electricity.

The invention consists, essentially, in providing an electricity-meter with a switch having mechanical means of holding it open to cut oil supply, a prepayment mechanism ad apted to release the switch and allow it to close upon insertion of a coin, and electromagnetic means for opening the switch automatically upon completion of a supply of a predetermined amount of electricity by means of a contact device actuated by the meter to close a shunt-circuit through the said switch and electromagnetic means. It will be seen that the moment the meter causes the contact device to close the shunt-circuit not only will the supply be cut off by the consequent opening of the switch, but the shunt will also be opened by the switch and the latter be held open simply by the mechanical means.

In carrying the invention into effect I prefer to employ an electrolytic electricity-meter having a float adapted to move with fall of level of the electrolyte due to the decomposing action of the current and provide means whereby the fall of the float actuates the contact device of the prepayment mechanism before referred to. Such an arrangement of the invention is shown as an example in the accompanying drawings, in which Figures 1 and 2 are plan and side elevation of a prepayment-meter constructed according to my invention. Figs. 3 and 4 are side elevation and partial plan showing coin in action. Fig. 5 is a front elevation showing meter and prepayment mechanism mounted within a box. Fig. 6 is a vertical section of the meter proper, showingfloat-actuated drum for operating the contact device which cuts off supply when complete. I

I mount two shafts 2 3, Fig. l, with their axes coincident and fix thereon two arms 4 5, the arm 5 having a lateral projection on its end adapted to be engaged by the arm 4 when the latter overtakes the arm 5, the two arms constituting a contact device, preferably of platinum or with platinum contact parts, and adapted to close an electric circuit, as will be hereinafter explained. Both arms 4 and 5 are held against backward rotation, the one by a ratchet 6 and pawl 7 and the other by a ratchet 8 and pawl 9. The arm 5 is adapted to be turned ahead of the arm 4 by means of a suitable prepayment mechanism, as will be hereinafter described, to a definite amount, depending on the number of coins or tokens inserted, and the arm 4 receives a forward travel from the meter or mechanism for measuring the amount supplied or consumed until it overtakes the arm 5 and contacts therewith, whereupon a circuit is closed and actuates an electromagnetic device to cut off further supply until the arm 5 is again set ahead. For example, I have shown the arm 4 with its shaft 2 connected to a train of wheels 50X, Fig. 1, having indexes registering on dials and actuated from the float of an electrolytic electricity-meter A by means of the corddrum R, as shown in Fig. 5. The action of the float will be clearly understood from Fig. 6, in which K is the float, having projections n to guide it in the tubular meter A. A cord r, passing over a drum R, is connected at one end to the float K and carries a counterpoise tat the other end. A pawl a and ratchet U transmit motion from the drum R to a train of wheels m X, having indexes registering on dials; but this registering mechanism may be omitted, desired. A detent and ratchet e V, Fig. 6, are provided to prevent backward rotation, or a pawl and ratchet 7 6, as shown in Fig. 1, may be provided. The arm 4 is thus caused to travel in relation to the registering movement of the indexes 10,

according to the consumption of current. The arm 5 is shown geared by toothed wheels 11 12 to the shaft 13 of a prepayment mechanism, which has a second shaft 14 in alinement with shaft 13. The shafts 13 and 14 are revoluble and adapted to belongitudinally displaced, but are pressed normally into the position indicated in Fig. 1 by springs 15 16. The contiguous ends of these shafts carry two disks 17 18, the opposing faces of which have each a groove 19 20, adapted to receive between them a coin of given value, and the opposite end of shaft 14 is extended through the side of the box to carry a milled disk 21. hen there is no coin in the grooves 19 20, the shaft 14 can be pushed in-and rotated by the milled disk 21 without acting on the shaft 13; but when a coin is dropped into said grooves it forms therewith a clutch whereby the shaft 13 is compelled to move with the shaft 14. The shaft 13 is prevented rotating in normal position by two pins 22, carried by its pinion 12, Fig. 4, which normally lie in holes in the frame 23. hen the requisite coin 24 is dropped into the grooves 19 20, the arm 5 may be set a given distance ahead by first pushing in the milled disk 21, thus pushing both shafts 13 14 until the pins 22 are out of the holes in the frame 23, as shown in Fig. 4, and then giving the disk 21 a half-turn to move the arm 5. In this movement the coin is carried round, and on the disk 21 being released the shafts 13 14 are returned by the springs 15 16, the pins 22 again lock the shaft 13, and the coin drops out below.

As a result of the above prepayment I cause the supply through the meter to be started and continued until the arm 4 overtakes the arm 5 by the following means: 25 is an electromagnet, and 26, Figs. 1 to 3, an armature mounted at one end of a lever 27, pivotally supported at 28 and carrying at its other end two iron points 29, adapted to be moved by the lever 27 into and out of two mercurycups 30, carried by an insulating-bracket 31. I may, however, use any equivalent switch or make-and-break device adapted to be operated electrically. I pivotally mount a catch or hooked lever 32 to engage and hold down the lever 27 at one end when the armature 26 has been attracted by the magnet 25 to open the switch 29 30. The catch-lever 32 is formed or provided with a disk or tray 33, adapted to be engaged and depressed by the coin 24, as shown in Fig. 3, to liberate the catch 32 from the lever 27, which thereupon tilts into the position in which the switch 29 30 is closed. The catch 32 and tray 33 are returned by a spring 34 after the coin reaches and drops through a slot 35 in the tray.

The electricity-meter A, Fig. 1, has its terminal 7) connected with one mercury-cup 30 by a conductor 37 and its other terminal 0 connected by a conductor 38 with the negative outer terminal 40, while the second mercury-cup is connected by a conductor 36 with the positive outer terminal 39. In this way a main circuit is provided through the switch 30 29 and electricity-meter A from the one terminal 39 to the terminal 40 if the switch 30 29 be closed.

A shunt-circuit is provided through the electromagnetic device and movable contacts 4 5 in the following manner: A conductor 41 leads from one mercury-cup 30 to the coil of the electromagnet 25 and a conductor 42 from the latter to the frame 23 of the contactarm 5, while the frame 44 of the contact-arm 4 is connected by a conductor 43 with the other terminal 40.

The mode of action is as follows: Before the insertion of a coin the switch-arm 27 is held by the catch 32 so as to keep the iron points 29 out of the mercury-cups 30, thus breaking both the main and shunt circuits, the parts having the position indicated in Figs. 1 and 2. In order to obtain a supply, a coin of requisite value is inserted in the slot Z, Fig. 3, and immediately drops into the grooves 19 20 of the related disks 17 18, Fig.

2, thus clutching these two disks together.

In order to insure the coin dropping into these grooves, the index 45 of the operatingdisk 21 should be vertical, or if slightly out it should be moved into a vertical position before the insertion of the coin. The operating-disk 21 is now pushed in, thereby pushing back shafts 14 13 and disengaging the pins 22, as before described and shown in Fig. 4. The operating-disk 21 is now given a half-turn and released. In this movement the coin 24 is carried round and engages the tray 33, causing the latter to tilt, as shown in Fig. 3, thereby releasing the catch 32 from the switch-lever 27 and allowing the iron points 29 of the switch to drop into the mercury-cups 30 and close the main circuit,whereupon a supply of current is started from terminal 39 through conductor 36, switch 29 30, conductor 37, meter A, and conductor 38. On the completion of the half-turn of the operating-disk 21 the coin will have made a complete half-turn and will coincide with the slot 35 in the tray33, thus enabling the latter to return under the action of its spring 34, bringing the catch 32 into the position indicated in dotted lines and enabling the coin 24 to drop below into a suitable receptacle. Upon the release of the operating-disk 21 the springs 15 16 return the shafts 13 14 to normal position, in which the shaft 13 is locked by the pins 22 against any rotation. In the course of the half-turn given to the shaft 13, as just explained, the latter will have turned one contact-arm 5 a given distance ahead of the contact-arm 4 by means of the gearing 12 11, Fig. 1, relative to the amount of current which is to be supplied for the coin inserted. As current is consumed it passes through the meter A, and as the float of the latter falls it I cording to the amount prepaid, the arm 4 will contact with the arm 5, thus closing the shuntcircuit through the electromagnet 25 by conductor 41 from the switch 29 30 to the coil of said magnet, thence through conductor 42, frame 23, contact-arms 5 and 4, frame 44, and conductor 43, the frames 23 and 44 being insulated one from another by insulatingbushings, as shown. The electromagnet 25 thus excited at once attracts the armature 26 and the consequent tilting of the lever 27 opens the switch 29 30, thus cutting off all current through the meter and the magnet; but the switch-lever 27 is prevented returning by the engagement of the catch 32, the parts now occupying normal position, as indicated in Fig. 2, and all supply of current is cut off until another coin is inserted. Several coins may be inserted in rapid succession, if desired, instead of inserting the coins inclividually as the value of each is consumed. By extending the left-hand wall of the downchute of the slot Z below the bottom of the other wall to almost touch the disks 1? 18, as shown in Fig. 2, the inserted coin will itself prevent backward rotation of the prepaymentindex, and the pawl and ratchet 8 9 may thus be supplemented or dispensed with.

Fig. 5 shows a suitable arrangement of the prepayment mechanism, registering-dials, and electrolytic meter within a case or box 50, which is provided at the front with upper and lower doors 51 52 and a hinged top 53. The registering and prepayment mechanism is mounted on a slide or shelf 55, supported on angle-irons, so as to be capable of'being easily withdrawn from the box, and the object of the upper door 51 and hinged top 53 is to render impossible unauthorized interference with the dials, as the front upper door 51 overlaps and secures the hinged lid 53 and shelf 55 and is adapted to be locked, while permitting the lower door 52 to be opened by authorized persons for the purpose of refilling the meter A and obtaining access to a drawer 54, containing the money accumulated from the prepayments.

I declare that what I claim is 1. In a prepayment electricity-meter, the combination of a meter, a main circuit, a shunt-circuit, a contact device actuated by the meter to close the shunt-circuit upon completion of a supply of a predetermined amount of electricity, a balanced switch in both circuits, electromagnetic means in the shunt-circuit adapted to actuate said switch to open both circuits with a sharp break under a slight magnetic pull upon closure of the shunt-circuit by the contact device, a catch adapted to hold the switch in said open position and a prepayment mechanism adapted upon insertion of a coin, to be moved by hand to mechanically force the catch off the switch and allow it to close, substantially as described.

2. In an electrolytic electricity-meter, the combination with a float therein adapted to move with fall of level of the electrolyte in the meter, of a revolubly-mounted contactarm, means for transmitting motion from the float to said arm to rotate it in one direction, a prepayment mechanism, a contact-arm adapted to be turned thereby to a definite amount ahead of the aforesaid meter contact-arm, a switch, a main circuit through said meter and switch, an electromagnetic device adapted to open said switch, a shunt-circuit through said switch, and electromagnetic device and contact-arms adapted to be closed when the me-' ter contact-arm'overtakes the prepaymentarm, and contacts therewith to excite the electromagnetic device and open the switch, thus.

opening both circuits and cutting off all supply, and mechanical means of preventing closure of the switch until the prepayment mechanism is again actuated upon insertion of a fresh coin.

3. In an electrolytic electricity-meter the combination with the prepayment mechanism and a switch adapted to be actuated by electromagnetic means to open the main circuit upon closure of a shunt-circuit, of a switchactuating lever adapted to be moved by the electromagnetic device to open the switch, a catch-lever adapted to engage and hold the said switch-lever in said open position, and a tray on said catch-lever having a slot adapted to permit of a given coin dropping through, said catch-lever being so disposed relative to the prepayment mechanism that a coin rotated by the latter is adapted to engage and depress said tray to release the catch-lever and allow the switch to close, substantially as described.

4. A prepayment electricity-meter comprising an electrolytic electricity-meter, a float therein adapted to move with fall of level of the electrolyte, dial-registering mechanism adapted to be actuated by said float, to register the amount of current supplied, a contactarm revoluble with said mechanism, and a prepayment mechanism adaptecl to be actuated on insertion of a coin to start the supply, and having a contact arm revoluble therewith and means adapted to be actuated electromagnetically when the one arm overtakes the other to automatically cut off the supply when complete for the value of the coin inserted, substantially as described.

In witness whereof I have hereunto signed my name, this 24th day of June, 1903, in the presence of two subscribing witnesses.

- BARKER NORTH.

Witnesses:

WILLIAM SCRUTON, DAN. CoA'rEs. 

